In 2017, at least two incidents occurred where a contractor violated the MS4 regulations. What is MS4? It is the Municipal Separate Storm Sewer System. Unlike sanitary sewer systems that collect water and send it to a treatment facility, MS4 regulations cover the storm water systems that collect water and discharge it directly into a body of water such as a river, stream or pond. The systems do not treat the water; therefore, only rain water can be put into them. MS4 is required by state law in census-urbanized areas.

 

So what is the issue for maintenance contracts? Unlike construction projects where silt fences and other best management practices are used to collect water that may have contaminants, most maintenance projects do not – particularly paving projects. Therefore, the contractor must take special care not to violate MS4 regulations. In the 2016 VDOT Road and Bridge Specifications book, Section 107.16 – Environmental Stipulations covers common pollutants and what the contractor must do. While specifically not stating the means and methods, the contractor must ensure water with pollutants does not leave the site. This is not dissimilar to pollution prevention requirements on regulated construction sites.

 

For paving and milling operations in MS4 covered locations, care must be taken to prevent pollution. When milling is completed at the end of the shift, it is common practice to wash down the milling head and housing to remove dust and cool the teeth. This wash water must be contained, captured and removed from the site for disposal. Failure to do so may result in issuance of a fine by the holder of the MS4 permit. To learn more about MS4 in your area, contact the VDOT District Office’s NPDES Coordinator.